Lamp socket



July 26, 1 38. Y c. M. Moss' 2,125,082

LAMP SOCKET Filed April 14, 1954 WITN ESS ES Patented July 26, 1938 UNITED STATES PATENT OFFICE LAMP SOCKET Pennsylvania Application April 14, 1934, Serial No. 720,602

3 Claims.

My invention relates, generally, to lamp sockets, and, more particularly, to sockets for double filament lamps which may be termed two-circuit sockets.

The object of my invention, generally stated, is to provide a lamp socket having a plurality of circuits which shall be of simple design and economical to manufacture and which may be used in conjunction with a control switch of any kind.

A more specific object of my invention is to provide for supporting and conveying current to an electric lamp having a plurality of filaments by means of a single lamp socket.

A further object of my invention is to provide a lamp socket of the above-identified character having a plurality of concentrically-disposed contact members and a centrally-disposed spring mounted contact member.

A further object of my invention is to provide, in a lamp socket of the above-described character, for resiliently mounting a central contact member in such manner that it may be depressed in one direction when the lamp is inserted in the socket and is constantly urged or biased in the opposite direction to maintain adequate pressure on the lamp base.

Another object of my invention is to provide a lamp socket having a centrally-disposed springbiased contact member comprising a single stem member adapted to function both as a terminal member and a contact member and being bodily movable within the socket.

Other objects of the invention will become apparent from the following description when read in conjunction with the drawing in which:

Figure 1 is a top plan view of the lamp socket embodying the principal features of my invention;

Fig. 2 is a sectional view taken along lines 11-11 of Fig. 1;

Fig. 3 is a similar view taken along line.

IIIIII of Fig. 1; Y

Fig. 4 is also a view similar to Fig. 2, taken along line IV-IV of Fig. 1;

Fig. 5 is a bottom plan view of Fig. 3, showing the concentrically-mounted contact members and the center contact member of the socket;

and

Fig. 6 is a view showing the details of the center contact element.

In practicing my invention in its broadest aspects, the lamp socket is so constructed that the lamp may be supported by screwing it into a shell element of the socket in the usual manner, the

shell element being used as the common contact element for both filaments of the lamp. The socket is also provided with two other contact elements adapted and arranged to engage corresponding contact terminals on the lamp base as it is screwed into the socket. One of these contact members is movable so that there will be no difiiculty in obtaining the proper contact engagement between all the contact elements of the socket and those of the lamp base.

Referring now to the drawing, there is illustrated an embodiment of my invention in the form of a socket for supporting and conveying current to a double filament lamp.

As will be observed, the socket comprises a main body member In of cylindrical shape having concentrically disposed annular projections II and I2 on the lower face thereof. The pro jection ll forms a large cylindrical opening or chamber in the bottom of the body member ID,

cal opening formed by the projetcion II and secured to the bottom face of the body member by means of screws or bolts M and I5. The contact element I3 is formed with threads l6 corresponding to the threads found on the base of an incandescent lamp.

The contact element l3 may be utilized as the common terminal for the two filaments in the lamp. However, in order to provide for conveying current to these filaments independently so that they may be controlled separately, there is provided a secondary contact element I7 and a central contact element Hi.

In this instance, the secondary contact I! is shown in the form of a ring member which is supported, as shown in Fig. 4, by means of an integral bracket portion I9 secured tothe lower face of the base ID by means of a suitable screw or bolt 20. The screw 20 also serves as the connecting terminal for this contact element.

It will be observed that the secondary contact element I1 is positioned directly beneath the open end of the annular projection l2 so that when the lamp base is screwed into the socket it forces the secondary contact element upwardly against the annular projection, which tightens the lamp base in the socket and insures a good contact.

The secondary contact I! engages a corresponding contact element on the end of the lamp base and may be most conveniently used to convey current to the low wattage filament of the lamp.

As will be readily understood, there is no difiiculty in obtaining the proper contact relation between the lamp base and the shell l3 and the secondary contact element ll. However, it is very difiicult to construct a satisfactory socket with more than two stationary contact elements.

In order that the circuit connection to the other filament of a double filament lamp may be made without difiiculty and maintained regardless of the exact position of the lamp base in the socket, the center contact element is is mounted within a central longitudinal opening 2| in such manner that it may be moved along the longitudinal axis of the socket and has its lower end or contact tip extending downwardly into the large cylindrical opening formed by the projection H.

As shown best in Fig. 6, the center contact element l8 comprises a body member 22 having a square head portion 23 and either a square or round stem. portion 26. The head portion '13 is provided with a suitable threaded opening disposed to receive a screw 25 in order to connect the lead-in wire to this terminal.

The body 22 is maintained in position in the opening 2| of the main body member ID by means of washers 26 and 21 and a spring 28. The body 22 is placed in the longitudinal opening 2| and its downward movement limited by the engagement of a shoulder formed by its head portion 23 with a corresponding shoulder in the base I B. The washer 25 is first placed on the stem 24 followed by the spring 28 and the washer 21 which is held in position on the bottom of the stem by peening or otherwise enlarging the tip thereof in a well-known manner.

As will be readily understood, when the center contact element is assembled, in the foregoing manner, the body 22 is continually biased in a downward direction and may be moved upwardly when engaged by the tip of the lamp base, thereby forming the necessary movable contact element of the socket.

In view of the foregoing description, it is apparent that the center contact element It is bodily movable along the longitudinal axis of the body member ID and because of its one-piece construction there is no difficulty encountered in maintaining contact between the tip of the lamp base and the supply conductor.

The center contact is usually used for the connection to the high wattage filament of the lamp since because of its construction, it is capable of carrying more current than the secondary contact element ll.

As shown in Fig. 3, the body member Ill is provided with suitable openings 29 through which mounting screws may be placed.

Although I have described a specific embodiment of my invention, it will be obvious to those skilled in the art that various changes may be made in the details of construction, such as in the proportion organization and the design of the several cooperating parts, without departing from the spirit of the invention as set forth in the app-ended claims.

I claim as my invention:

1. A lamp socket comprising a unitary body member of molded construction having a central longitudinal opening and concentrically disposed inner and outer annular projections on one face thereof forming an end recess, a plurality of concentrically-disposed stationary contact elements mounted within the recess formed by the outer projection, one of said contact elements being adjacent the outer projection and the other adjacent the inner projection, a onepiece movable contact element supported by and bodily movable within the central longitudinal opening of the body member and having one end thereof extending into the recess formed by the outer projection and the opposite end exposed for direct attachment to a current conductor, and spring means interposed between one end of the movable contact element and the bottom of the end recess for biasing said contact elei end of a lamp base, a movable contact member J slidably disposed within and supported by the longitudinal central opening of the body mem ber, separate means for resiliently urging the movable contact member toward the open end of the body member, and means at one end of f the movable contact member for attaching a current conductor thereto.

3. A lamp socket comprising a unitary body member having a central longitudinal opening therethrough and concentrically disposed inner and outer annular projections on one face thereof forming a recess, a stationary contact shell disposed within the outer projection, a fixed contact ring mounted within the outer projection in close proximity to the inner projection to engage a contact ring on a lamp base, a movable contact element mounted within the central longitudinal opening and extending to a point within the recess formed by the outer projection to be engaged by theend of a lamp r base, and a separate spring memberconcentrically positioned about the movable contact element for resiliently biasing it toward the contact shell.

CHARLES MoL. MOSS. 

